1. Field of the Invention
This invention relates to transparent soap bars. More specifically, the present invention relates to transparent soap bars which exhibit improved lathering and foaming characteristics due to the presence of alkyl polyglycosides.
2. Description of the Related Art
Transparent soap bars are normally milder than opaque bars. These soaps depend for their distinctive appearance upon the fact that soap is deposited from alcoholic solution in a transparent, ultramicrocrystalline form. The incorporation of glycerol and sugars also tend to cause soap to assume this form. The effect is entirely physical, and depends upon the conditions under which the soap crystallizes rather than the presence of alcohol or any other substance in the finished soap cake. Thus, a transparent soap made with the aid of alcohol retains its appearance after most of the alcohol has been evaporated from it.
Transparent soaps vary greatly in composition. They may be prepared simply by dissolving soap flakes in alcohol and then driving off the greater part of the alcohol. Such a product will not be greatly different in composition from the original soap flakes. A more usual method of manufacture, however, is to add alcohol and glycerol, in the proportion of about two parts of alcohol to one of glycerol, to a hot saponified batch of semi-boiled soap until a rapidly cooled sample is clear, after which the batch is framed in the usual way. Sugar may also be added. The fats used in transparent soaps usually are tallow and coconut oil. Up to about 30% castor oil is often used in the fat charge, as the presence of this oil reduces the amount of alcohol, glycerol or sugar required to render the soap transparent. The anhydrous soap content of transparent soaps is usually well under 50%.
There has always been a need to increase the lathering and foaming characteristics of transparent soap bars by inclusion of various types of surfactants. However, it has been found that when a synthetic surfactant is added to a transparent soap formulation, the resulting bar is not transparent. It is, therefore, an object of the present invention to increase the lathering and foaming characteristics of transparent soap bars without causing a reduction in the transparency of the bar.